Twin-tetrode electron discharge device having two-wire lecher line input and u-shapedmetal strip output means



1965 E. G. DORGELO ETAL 3,202,865

TWIN-TETRODE ELECTRON DISCHARGE DEVICE HAVING TWO-WIRE LECHER LINE INPUTAND U-SHAPED METAL STRIP OUTPUT MEANS Filed Dec. 25, 1960 INVENTORS.Z'DUAZZZ) DORGELO afiwlv FINN BY Aaflvz 6 a 2 2 g r L. M O 6 H /2/.. 61| 1 KK n United States Patent TWEN-TETRODE ELECTRQN DHSCHARGE DEVICEHAVINS TiJG-WIRE LECi-ER LINE INPUT AND (l-SHAPED METAL STRIP DUTPUTMEANS Eduard G. Dorgelo, Huntington, and John Finn, Woodhaven, N.Y.,assiguors to North American Philips Company, line, New York, N .Y., acorporatian of Delaware Filed Dec. 23, 19613, Ser. No. 77,998 8 Claims.(Cl. 315-39) Our invention relates to an electron discharge tube, and inparticular to electron discharge tubes of the twintetrode type.

One object of the invention is to provide a compact, rugged, high-vacuumelectron discharge tube.

Another object of the invention is to provide an electron discharge tubewhich is extremely resistant to mechanical shock and vibration.

A further object of the invention is to provide a twintetrode electrondischarge and a circuit therefor in which feedback is prevented.

These and further objects of the invention will appear as thespecification progresses. In accordance with our invention, the envelopeof the tube comprises a ring of insulating material, such as ceramic,closed on both sides by metal plates serving as, or supporting, anodes.Inside of the ring a pre-assemble d tube structure is mounted whichincludes a cathode, two separate control grids and a second or screengrid surrounding both control grids and the cathode. Leads, connected tothe cathode, filament (in the case of an indirectly heated cathode) andthe screen grid extend in a radial direction through the ring in a planemidway between the metal end covers. Similarly, leads extend through thering in a radial direction and are connected to the control grids, butare diametrically opposite to the leads for the cathode and the screengrid.

The cathode, control grids and screen grid are held together by twodiscs made from insulating material like natural mica, synthetic mica orceramics. The rims of these discs fit into or onto the anodes in such away that once the envelope is totally closed, the internal system isfirmly held in place and resistant to shock and vibration.

Since complete shielding between the input and output circuits is notpossible, a special circuit is employed to prevent feedback. An inputsystem in the form of a twowire Lecher line is connected between thecontrol grids while a U-shaped metal strip is connected between bothanodes. The input and output systems are positioned that their planes ofsymmetry form an angle between them of less than 90.

The invention will be described in connection with the accompanyingdrawing in which:

FIG. 1 is an elevational view, partially in section, of the tube;

FIG. 2 is a sectional view along the lines IIII of FIG. 1, and

FIG. 3 is a perspective of the tube and its associated input and outputcircuits.

The tube as shown in FIGS. 1 and 2 is a double tetrode in which theelectrode structure 1 is located between a pair of metal end plates 2and 3 which serve as anodes. The electrode structure includes a cathode4, which may be indirectly heated by a filament (not shown), a pair ofcontrol grids 5 and 5, and a screen grid 7 which surrounds the controlgrids. The electrodes are supported by insulating discs 8 and 9preferably of mica (natural or synthetic) or ceramic material which fitinto slots 10, 11, 12, and 13 in the anodes.

A ceramic ring 14 is sealed betweenextensions 15, 16, and together withthe anodes form the envelope of the 3,262,856 Patented Aug. 24, 1965 icetube. Through this ring extend the lead-in conductors for the electrodeswithin the tube.

One pair of lead-in conductors 17 and 18, located on one side of a planeof symmetry, connect, respectively, to each of the control grids 5 and6. Three lead-in conductors 19, 20, and 21, in the other side of theplane of symmetry connect respectively to the filament, cathode andscreen grid. Thus, lead-in conductor 19 connects to a terminal 22 of thefilament; lead-in conductor 20 connects to the cathode terminal 23 andthe other filament terminal 24. Lead-in conductor 21 connects to thescreen grid 7.

Terminal connections25 and 26 extend outward from anodes 2 and 3respectively to which an output circuit such as shown in FIG. 3 may beconnected. In this arrangement, the output circuit 27 is a copper stripbent in the shape of a double U. The input system 28 is a normaltwo-wire Lecher system which is connected to the control grids and thecathode.

Since complete shielding between the input and output circuits cannot beprovided, feed-back is prevented by positioning the Lecher wire systemrelative to the output circuit such that the symmetry planes of bothcircuits form an angle which is less than All coupling, electrical andmagnetic, will thus compensate and there will be no feed-back. Ifnecessary, the angle can be changed slightly to compensate for possibleasymmetries in the tube itself.

The tube described herein is extremely compact, rugged and resistant tomechanical shock. The invention, however, is'not limited to tetrodes butincludes other electrode combinations as well.

Therefore, while the invention has been described with reference to aspecific embodiment and in connection with specific applications, we donot wish to be limited to that which is described. The invention isdefined in the appended claims which should be broadly construed.

What we claim is:

1. An electric discharge tube comprising an envelope constituted by apair of conductive members separated by an annular insulating member,cathode and control electrodes, insulating members within said envelopesecured in said conductive members for supporting said electrodes inspaced relationship within said envelope, lead-in conductors extendingradially in opposite directions through said annular insulating memberand connected to said cathode and control electrodes respectively, aportion of one of said conductive members constituting an anode, and alead-in conductor extending outwardly from said conductive memberconnected to said anode portion.

2. An electric discharge tube comprising an envelope constituted by apair of conductive members separated by an annular insulating member,cathode, control and screen electrodes, insulating members within saidenvelope secured in said conductive members for supporting saidelectrodes in spaced relationship within said envelope, lead-inconductors extending radially in opposite directions through saidannular insulating member and connected to said cathode, control, andscreen electrodes respectively,a portion of one of said conductivemembers constituting an anode, and a lead-in conductor extendingoutwardly from said conductive member connected to said anode portion.

3. An electric discharge tube comprising an envelope constituted by apair of conductive members separated by an annular insulating member, acathode electrode, a pair of control and screen electrodes, insulatingmembers within said envelope secured in said conductive members forsupporting said electrodes in spaced relationship within said envelopeon opposite sides of said cathode, lead-in conductors extending radiallyin opposite directions through said annular insulating member andconnected to 3 said cathode and control and screen electrodesrespectively, anode electrodes on opposite sides of said cathodeconstituted by portions of said conductive members, and leadinconductors extending outwardly from said conductive members connected tosaid anode portions of said conductive members.

4. An electric discharge tube comprising an envelope constituted by apair of conductive members separated by an annular insulating member,cathode, control and screen electrodes, insulating members within saidenvelope secured in said conductive members for supporting saidelectrodes in spaced relationship within said envelope, lead-inconductors extending radially in opposite directions through saidinsulating member and connected to said cathode, control and screenelectrodes respectively, one of said conductive members constituting ananode, and a lead-in conductor connected to and extending outwardly fromsaid anode. V

5. An electric discharge tube comprising an envelope constituted by apair of conductive members separated by an annular insulating member, acathode electrode, control and screen electrodes, insulating memberswithin said envelope secured in said conductive members for supportingsaid electrodes in spaced relationship within said envelope on oppositesides of said cathode, lead-in conductors extending radially in oppositedirections through said insulating member and connected to said cathode,control, and screen electrodes respectively, one of said conductivemembers constituting an anode, and a lead-in conductor connected to andextending outwardly from said anode.

6. A circuit arrangement comprising an electric discharge tube includingan envelope constituted by a pair of conductive members separated by anannular insulating member, cathode and control electrodes, insulatingmembers Within saidenvelope secured in said conductive members forsupporting said electrodes in spaced relationship Within said envelope,lead-in conductors extending radially in opposite directions throughsaid insulating member and connected to said cathode and controlelectrodes respectively, an input system comprising a twowire Lechersystem connected between said lead-in conductors, a portion of each ofsaid conductive members constituting anodes, and an output systemconstituted by a pair of conductors connected between said anodes, saidinput and output systems having intersecting planes of symmetry whichform an angle therebetween of less than 90.

7. A circuit arrangement comprising an electric discharge tube includingan envelope constituted by a pair of conductive members separated by anannular insulating member, cathode and control electrodes, insulatingmembers within said envelope secured in said conductive members forsupporting said electrodes in spaced relationship within said envelope,lead-in conductors extending radially in opposite directions throughsaid insulating member and connected to said cathode and controlelectrodes respectively, an input system comprising a two wire Lechersystem connected between said lead-in co11-. ductors, a pair of anodeelectrodes each constituted by a portion of said conductive members, andan output system comprising a U-shaped conductive metal strip connectedbetween said anodes, said input and output systems having intersectingplanes of symmetry which form an angle therebetween of less than 8. Acircuit arrangement comprising an electric discharge tube including anenvelope constituted by a pair of conductive members separated by anannular insulating member, a cathode, a pair of control electrodes,insulating members within said envelope secured in said conductivemembers for supporting said electrodes in spaced relationship withinsaid envelope on opposite sides of said cathode, lead-in conductorsextending radially in opposite directions through said insulating memberand connected to said cathode and control electrodes respectively, aninput system comprising a two wire Lecher system connected between saidlead-in conductors, a pair of anodes on opposite sides of said cathodeeach constituted by a portion on one of said conductive members, and anoutput system comprising a U-shaped conductive strip connected betweensaid anodes, said input and output systems having intersecting planes ofsymmetry which form an angle therebetween of less than 90.

References Cited by the Examiner UNITED STATES PATENTS 2,158,114 5/39Fritz 315-393 X 2,226,653 12/40 Allerding 3l539 2,236,016 3/41 Steenbeck31539 X 2,441,792 5/48 Brian 313-250 X 2,454,560 11/48 Lafierty 315-392,735,941 2/56 Peck 333-82 X 2,750,535 6/56 Doolittle et a1. 31539 X2,803,782 8/57 Diemer 315-39 X 2,910,607 10/59 McCullough et al. 313250X GEORGE N. WESTBY, Primary Examiner.

RALPH G. NILSON, Examiner.

8. A CIRCUIT ARRANGEMENT COMPRISING AN ELECTRIC DISCHARGE TUBE INCLUDINGAN ENVELOPE CONSTITUTED BY A PAIR OF CONDUCTIVE MEMBERS SEPARATED BY ANANNULAR INSULATING MEMBER, A CATHODE, A PAIR OF CONTROL ELECTRODES,INSULATING MEMBERS WITHIN SAID ENVELOPE SECURED IN SAID CONDUCTIVEMEMBERS FOR SUPPORTING SAID ELECTRODES IN SPACED RELATIONSHIP WITHINSAID ENVELOPE ON OPPOSITE SIDES OF SAID CATHODE, LEAD-IN CONDUCTORSEXTENDING RADIALLY IN OPPOSITE DIRECTIONS THROUGH SAID INSULATING MEMBERAND CONNECTED TO SAID CATHODE AND CONTROL ELECTRODES RESPECTIVELY, ANINPUT SYSTEM COMPRISING A TWO WIRE LECHER SYSTEM CONNECTED BETWEEN SAIDLEAD-IN CONDUCTORS, A PAIR OF ANODES ON OPPOSITE SIDES OF SAID CATHODEEACH CONSTITUTED BY A PORTION ON ONE OF SAID CONDUCTIVE MEMBERS, AND ANOUTPUT SYSTEM COMPRISING A U-SHAPED CONDUCTIVE STRIP CONNECTED BETWEENSAID ANODES, SAID INPUT AND OUTPUT SYSTEMS HAVING INTERSECTING PLANES OFSYMMETRY WHICH FORM AN ANGLE THEREBETWEEN OF LESS THAN 90*.